1. Field of the Invention
The present invention relates to a hearing aid with different assemblies for receiving further processing and adjusting an audio signal to the hearing ability of a hearing impaired person, wherein digital processing is performed in the hearing aid.
2. Description of the Prior Art
In the case of a hearing aid wearer having extremely low residual hearing, the hearing disability Is usually such that a partial cutoff of high pitched sounds occurs in a frequency region between 1 kHz and 2 kHz. In this cutoff of high pitch, the region between the hearing barrier and the discomfort barrier is very narrow, such that the region of an audio signal which is important for speech recognition cannot be satisfactorily detected, even given very high amplification. On the other hand, it should be avoided that the amplification becomes too high and the discomfort barrier is thereby crossed. The dynamic of the hearing field is about 100 dB in someone with normal hearing and can recede to 10 dB in a hearing-impaired person. Thus far, attempts to bring about an amplification adjustment in the hearing field have been accompanied by uncomfortable side effects--such as feedback-produced whistling tones or other acoustical disturbances--due to the high amplification.